“”EvoPsych 101: Rats and people are the same, but men and women are different.

—Anonymous

Evolutionary psychology (EP) attempts to explain how and why complex human behaviours emerged as a result of evolution of the humans and the human brain. This includes fitness advantages that such behavior gives, i.e., by natural selection. In the broadest sense, behaviors or social constructs are seen as adaptations in the same way as physical adaptations. However, evolutionary psychology also investigates behaviors as a by-product of natural selection (or "spandrels," to use Stephen Jay Gould and Richard Lewontin's term[1]) or simple evolutionary noise.

Evolution's mechanisms of mutation and natural selection have been very successful in explaining most aspects of human biology, and so far has had some success in explaining why many complex human behaviour exist throughout the human race. However, evolutionary psychology as a field is notoriously full of woo and cranks producing theories that are either proven wrong or cannot be disproven to promote bigotry. Examples include the idea that black people and women have not evolved the same ability to understand science as white men[1], that standards of beauty not evident outside the West are actually universal[2], and that black women have not evolved to be as good looking as women of other races[3]. More scientific studies by actually qualified evolutionary psychologists actually do help explain beauty preferences seen throughout the human race[4], along with many other features of human behaviour.

It is important to point out that evolutionary psychology is not a scientific non-starter like, say, homeopathy or intelligent design. Unlike these pseudointellectual excrescences regrettably misguided notions, evo-psych can, both in theory and in practise, produce well-founded conclusions.

Those interested in it should know, however, that even its least controversial and best-supported claims are intensely prone to distortion in the non-technical press and especially on the Internet. Just as Darwin's theory of natural selection was almost immediately perverted to justify cruel bigotry (Social Darwinism, eugenics), so evolutionary psychology is readily twisted to buttress prejudice. This does not make evolutionary psychology wrong, any more than the brutality of Social Darwinism made evolutionary theory wrong, but it does suggest that claims rooted in it should be assessed very carefully, both by those reading them and those writing them.

Evolutionary psychology has one basic premise: that human behaviour and cognition (collectively known as psychology) are governed to a great extent by Darwinian evolution. In other words, evolutionary psychology proposes that genetics is an important mechanism behind shaping psychology. When evo psychs formulate hypotheses, they try to use the Darwinian evolutionary history of humans, even though there is little evidence to corroborate their specific account.

Evolutionary psychology attempts to provide explanations for certain human behaviours. However, whether or not these generated explanations can then be established as scientifically-plausible or consistent is a separate question.[2] Areas in which an evolutionary approach to psychology is often applied include sex, morality, religion, and in-group/out-group effects.

While no scientist worth their salt will dispute that humans are the product of evolution, they will posit that they are a product of culture as well. A very clear picture has emerged in the literature and it goes against evolutionary psychology's main assumption — recall that they claim human psychology is governed to a great extent by Darwinian evolution. So, it is not that human psychology is not in part governed by our evolutionary history, but that social and cultural (i.e., on the levels of analysis above genetics) factors override the genetic layer in the overwhelming number of cases.[3] What this means is that many of the explanations and hypotheses evo psychs propose are fundamentally misplaced, leading to begging the question.[4]

In general, the idea of applying natural selection to human behaviour is controversial.[5] The reason is that in order for natural selection to occur, a trait must both be genetically inherited and exposed to sufficient selective pressure.

In studies of animal behaviour, the first requirement can usually be assumed in animals that lack cultural transmission. In humans, it is often not possible to establish whether or not given behavioural traits have a genetic component, as controlled experiments are not available for ethical and historical reasons, and workarounds such as twin studies often suffer from fatal flaws.[6] A further problem exists in that the definition of a discrete 'trait' is difficult to achieve; a behavioural trait exists in a behavioural context, and cannot be separated out the way that 'eye colour' can.[5]

In regard to the presence or absence of selective pressure, critics allege that much of evolutionary psychology's claims about selective regimes are pseudoscientific in nature, as proposals about particular selective pathways often cannot be theoretically disproven. In a broader sense, they allege that EP has failed to produce any new insights into human evolution that move beyond a purely speculative character, remaining at the level of generating hypotheses without having generated evidence to build upon these initial hypotheses.[7][8] As such, it hasn't matured into a field of study analogous to other areas of biology, remaining merely a novel proposal.

Proponents and critics alike are prone to making straw man arguments in both popular literature and sometimes scholarly literature. First, critics of EP are prone to dismissing it as genetic determinism, although such claims are rarely, if ever, made by proponents.[9]

On the other side, self-righteous promoters of EP (and especially its pop incarnations) will straw man critics as denying biology, "social constructionists," "politically correct," or even "radical feminists."[10] However, prominent EP critics such as David J. Buller do not repudiate that the human brain is the product of evolution; he divides EP into what he sees as upper-case "Evolutionary Psychology" (i.e., EP of the Flintstones variety) and lower-case "evolutionary psychology" based on better research and a broader view of evolutionary theory.[11][12] Similarly, Stephen Jay Gould argued that evolutionary psychology was only problematic insofar as it was concerned with finding selective, adaptationist explanations to the exclusion of others; he viewed human cognition as a spandrel that, once evolved, became subject to cultural and social factors.[13] This has led some to differentiate between two "senses" of evolutionary psychology in the sense that Buller has. "Capital EP" has also been referred to as "narrow-sense EP" or the "Santa Barbara school" due to its association with certain key assumptions and specific researchers.[14] Many criticisms of evolutionary psychology are directed at this narrow-sense of EP.

EP as genetic determinism. In some cases this is genuinely a straw man, as EP does attempt to describe the interaction between genes and environment in certain cases. EP generally claims that environmental input is necessary for genetic programs to operate.[15] However, in situations where there is an unambiguous interaction between genes and environment (for example, human height is determined both by genetics and nutrition), both the genetic and environmental component of the given trait can be independently established to some degree. Critics allege that EP often imposes no requirement that a given behavioural trait be established as having a genetic component or overestimates the influence of that component. In many cases, EP assumes the genetic component to exist, and assumes that it has a substantive impact on human behaviour, when neither clause has actually been shown to be true.[5]

EP relies on guesswork about a hypothesised "Environment of Evolutionary Adaptedness" (EEA) because little is known about the environment of the late Pleistocene. The EEA does not refer generally to one single evolutionary environment, but specifically the environment in which a specific adaptation developed.[16] Critics charge that this enables proponents of EP to shift the ground in debates and create a situation in which no EP claim can ever be disproven, as a new EEA can be established any time an old one is shown to be unlikely, a hallmark of pseudoscientific thinking.

EP is selection-centred and adaptationist. While some EP crosses into Lamarckian "hyper-adaptationist" territory and Panglossian thinking, much research in EP explains certain psychological phenomena as by-products (or "spandrels")[17] Stephen Jay Gould regarded evolutionary psychology as a potentially legitimate field of research, and lamented that it was held in thrall by adaptationist, selection-centred approaches to problems, while actual human behaviour may not have been shaped by selective evolutionary processes.[18] EP can and does cross into the territory of hyper-adaptationist, speculative, unfalsifiable "just-so stories." A number of concepts, findings, and methodologies in the field have been criticized for being implausible or false by the standards of neuroscience,[19]evolutionary biology,[14][20][21] and anthropology.[22] Application of pop EP ideas, both by pop-science writers such as Steven Pinker[23] and by fields outside of traditional EP[24] have, again, been snarkily referred to as "Flintstones thinking."

EP ignores proximate explanations of psychological phenomena. EP attempts to explain proximate explanations provided by cognitive, social, etc. psychology with an ultimate evolutionary explanation. These explanations are not mutually exclusive, but complementary. However, the issue is whether or not the "ultimate evolutionary explanation" is ever necessary to explain observed phenomena to begin with. EP proposals often fail to pass the test of Occam's Razor, failing to establish that EP provides an explanation for data that can't be explained with more mundane approaches.

EP is unfalsifiable, In some cases, EP generates explanations for behaviour that cannot be falsified, opening it up to charges of classical pseudoscience. One example is the changing EP explanations for traits such as altruism, in which multiple EP explanations have been put forward to explain the trait. Ground can be shifted between group selection,[25]reciprocal altruism and kin selection; if one explanation is shown to be inappropriate, the other can be invoked.

EP relies on the assumption of massive modularity. EP posits domain-specific modules that are shaped by natural selection to perform a specific task as well as claiming that the brain is composed largely of these modules (hence "massive modularity").[26] Critics contend that neuroscientific data does not support massive modularity.[19][27][28]

The mainstream media and pop sciencelove evolutionary psychology. In the specific cases or studies brought to the public's attention in newspaper articles, situations are often over-simplified to the point of being plain silly. Even qualified scientists who should know better can sometimes not resist the temptation to attribute every behavior that is (stereotypically) associated with a particular gender in contemporary society is actually the result of something our remote ancestors did to survive on the savannah. In fact evolutionary psychology, at least in its "popular" incarnation, can be an example of using "science" to imbue just-so stories with an air of credibility that actually justifies sexism and discriminatory behavior.[29]

An example is a supposed "study"[30] which explains why boys prefer blue and girls prefer pink. In the view of pop-evolutionary psychology, this is because women being gatherers and men being hunters, liking pink was most likely to allow you to find berries so women grew to be attracted to pink. So far, so common sense, however, the idea completely ignores many established facts (and blueberries). Such that colour preferences change from place to place, and even that in the Western world (where the concept of gender-specific colours is strongest) 100 years ago it was reversed; i.e., the soft colour of blue was associated with the Virgin Mary, and was thus feminine, while men preferred associations with strong, passionate colours such as red and pink. Another colour that's now seen as feminine, purple, was once associated with the Roman Empire, and with it, was seen as masculine back in the day. Indeed, a purple cloak was part of the Roman Emperor's regalia. To "wear the purple" was a euphemism for assuming this position, and the word itself became used for royalty in general.

Another example of how evolutionary psychology can go in a wrong direction is the work of Kevin B. MacDonald, who uses evolutionary psychology to explain stereotypical Jewish characteristics as being part of a group evolutionary strategy. His trilogy of books on the subject, especially The Culture of Critique (1998), has been called anti-Semitic for its assertion that Jews gravitate toward politics to promote policies in opposition to the dominant culture. In 1995 he was elected to a six year term on the executive council of the Human Behavior and Evolution Society, but by 2007 he had increasingly associated on a working level with anti-Semitic and white nationalist groups, causing the California State University at Long Beach, where he is a professor, to publicly distance itself from his views. In 2010 he became the director of the newly-founded American Third Position political party. His "theory" essentially asserts Jewish biological superiority, but turns this around and uses it to argue that anti-Semitism is justified as "self-defense."[31]

Although the field explicitly calling itself evolutionary psychology is relatively new, the idea goes back to Charles Darwin. Darwin's works The Descent of Man and The Expression of the Emotions in Man and Animals included applications of evolutionary thought to psychology. Other evolutionary approaches to human psychology and behavior have variously gone under the names of "sociobiology," "human behavioral ecology," "gene-culture co-evolution," and "human behavior and evolution."[32] Some critics have contended that evolutionary psychology is a rebranding of sociobiology.[33] While a number of former sociobiologists have moved into the field of evolutionary psychology, the focus on psychological mechanisms is what distinguishes the two approaches. As Leda Cosmides and John Tooby write: "... in the rush to apply evolutionary insights to a science of human behavior, many researchers have made a conceptual 'wrong turn,' leaving a gap in the evolutionary approach that has limited its effectiveness. This wrong turn has consisted of attempting to apply evolutionary theory directly to the level of manifest behavior, rather than using it as a heuristic guide for the discovery of innate psychological mechanisms."[34]

↑Stephen Jay Gould penned a scathing attack entitled Darwinian Fundamentalism, yet he believed religion to be an evolutionary spandrel, which has become a dominant view in EP in agreement with Gould as set forth in works like Scott Atran's In Gods We Trust and Pascal Boyer's Religion Explained. However, there is no irony here, as Gould explicitly described evolutionary psychology as a potentially fruitful field, if only it moved away from a preoccupation with adaptationism.